1. Field
Provided is a fusion protein including a targeting moiety, a cleavage site, and a cell membrane penetrating domain, a conjugate including the fusion protein and a bioactive substance, and medical uses relevant to the fusion protein and/or the conjugate.
2. Description of the Related Art
Various technologies for intracellular delivery of macromolecules such as proteins have been developed and spotlighted as a new therapeutic strategy. However, they have difficulties in accurately targeting to target cells or target organs. To solve such problems, there have been many studies on cell membrane penetration of proteins.
A protein transduction domain (PTD) was first suggested on the ground of the finding that TAT protein from Human Immunodeficiency Virus 1 (HIV-1) can be delivered inside a cell when it is added to a cell culture medium. Thereafter, drosophila antennapedia (Antp) homeotic transcription factor and herpes simplex virus-1 DNA binding protein VP22 were also reported to be capable of penetrating a cell membrane, thereby being introduced into a cell.
Based on the fact that a fusion protein wherein PTDs are linked to other peptides or proteins can be delivered into a cell, various attempts have been made to transfer drugs, peptides, proteins, and the like, for therapeutic purpose, into a cell using the PTDs.